I've been trying to devise a system whereas business in my story are rewaded a certain number of 'points' for 'green' practices. The more points a business scores, the lower it's taxes. Money from such tax is then rerouted into a loan system.....so businesses starting out can draw on it to make their business' more green.

Established business may request use of the money, as long as it's directed into things that improve it's 'green' score.

It needs work to get all the bugs out, but that's the proto-version, anyway.